In this video, we're going to begin our lesson on the classes of connective tissue. Recall from our previous lesson videos that connective tissue is the most diverse primary type of tissue in terms of both its structures and its functions. Because connective tissues are so diverse, they can actually be grouped in slightly different ways. You'll find that different textbooks and different professors can group connective tissues in slightly different ways. Here in this video, we're going to explain how we've strategically decided to group connective tissues in our lesson.
In this lesson, we are going to be grouping connective tissues into 2 major classes that you can see numbered down below, number 1 and number 2. The 1st major class of connective tissue in our lesson is connective tissue proper, which is also sometimes referred to as general connective tissue or fibrous connective tissue. The 2nd major class of connective tissue in our lesson is specialized connective tissue. Connective tissue proper is sometimes referred to as general connective tissue because these tissues tend to have more generalized functions that are not really specific or limited to any particular body system, body area, or body process. Instead, these generalized functions tend to be more basic and fundamental, more widely utilized throughout multiple body systems and areas.
The ground substance of these tissues tends to be gelatinous or more of a semi fluid, something in between a solid and a liquid. Connective tissue proper or general connective tissue, is also sometimes referred to as fibrous connective tissue because these tissues tend to be really rich in terms of their protein fibers that are found in their extracellular matrix. These protein fibers are often pretty conspicuous or distinct and easily seen under a light microscope. Connective tissue proper will always include both loose and dense connective tissues. As we move forward in our course, we'll be able to talk more about loose connective tissues and dense connective tissues.
The 2nd major class of connective tissues in our lesson is specialized connective tissue. As its name implies, these tissues tend to have more highly specific functions unique to the particular tissue. These specific functions tend to be limited to just one or a few body systems. The ground substance of these tissues is either a solid or a liquid, rather than being gelatinous. Specialized connective tissue will include cartilage, bones, and blood and lymph.
Cartilage and bones do have protein fibers in their extracellular matrix, but they tend to be a bit harder to see under a light microscope without specialized staining techniques. Blood and lymph do not really have protein fibers in their extracellular matrix. Below, we are showing you how we are grouping connective tissues in our lesson. Connective tissues are grouped into connective tissue proper, which includes loose and dense connective tissues, and specialized connective tissues, which include cartilage, bone, and blood and lymph.
Down below, we have a scale or a spectrum of the ground substance viscosity in the extracellular matrix or how thick the ground substance is. On one end, we have a rock-hard solid ground substance. On the other end, we have a liquid ground substance. Connective tissue proper, which includes loose and dense, they tend to have more of a gelatinous ground substance, more of a semi fluid in between a solid and a liquid. Specialized connective tissues will have a solid or a liquid ground substance, with bone and cartilage having a more solid ground substance, while blood and lymph have a liquid ground substance.
This here concludes our brief introduction to the classes of connective tissue. As we move forward in our course, we'll be able to talk about each of these connective tissues in their own separate videos in more detail. I'll see you all in our next video.
